Adjusting The Idle Speed; Checking The Spark Plug - Stihl MM 55 Manual De Instrucciones

Adjusting the idle speed

The idle speed adjusting screw (LA)
must usually also be adjusted whenever
the low speed adjusting screw (L) has
been adjusted.
: Let engine warm up for approx.
3 minutes
Engine stops when idling
: Slowly turn the idle speed adjusting
screw (LA) clockwise until the
engine runs smoothly – the tool
must not move
Tool moves when engine idles
: Turn the idle speed adjusting
screw (LA) counterclockwise until
the tool stops, then continue in the
same direction for between 1/2 and
one turn
Speed is erratic when idling, engine
stops despite adjusting the LA screw,
poor acceleration
: The idle setting is too lean –
turn the low speed adjusting
screw (L) counterclockwise
(approx. 1/4 turn) until the engine
runs smoothly and accelerates
correctly
MM 55, MM 55 C
Speed is erratic when idling
: The idle setting is too rich –
turn the low speed adjusting
screw (L) clockwise (approx.
1/4 turn) until the engine runs
smoothly and still accelerates
correctly
English / USA

Checking the Spark Plug

Wrong fuel mix (too much engine oil in
the gasoline), a dirty air filter and
unfavorable running conditions (mostly
at part throttle etc.) affect the condition of
the spark plug. These factors cause
deposits to form on the insulator nose
which may result in trouble in operation.
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